diff --git a/ui/src/components/usage/UsagePage.tsx b/ui/src/components/usage/UsagePage.tsx
index e7f4800..81ebb65 100644
--- a/ui/src/components/usage/UsagePage.tsx
+++ b/ui/src/components/usage/UsagePage.tsx
@@ -91,6 +91,7 @@ function rangeFor(preset: Preset, customFrom: string, customTo: string): { from:
   }
 }
 
+const CHART_H = 176; // px — stacked-bar plot height (was the h-44 / 11rem class)
 const GW = '#6366f1'; // indigo-500 — gateway (source axis)
 const DR = '#22c55e'; // green-500 — direct (source axis)
 const OTHER_COLOR = '#94a3b8'; // slate-400 — folded 'other' bucket
@@ -357,20 +358,21 @@ function StackedBars({
       <div className="flex items-center justify-between mb-3">
         <span className="text-xs font-medium text-slate-500 uppercase tracking-wide">{t('chart.tokensTitle')}</span>
       </div>
-      <div className="flex items-end gap-1 h-44" role="img" aria-label={ariaLabel}>
+      {/* Bar heights are computed in pixels off CHART_H, not percentages: a
+          percentage-height chain inside this flex column collapses to zero
+          because the column items aren't given a definite height. */}
+      <div className="flex items-end gap-1" style={{ height: CHART_H }} role="img" aria-label={ariaLabel}>
         {series.map((b) => {
           const sum = bucketTotal(b);
-          const hPct = maxBucket > 0 ? (sum / maxBucket) * 100 : 0;
+          const barPx = maxBucket > 0 ? Math.max((sum / maxBucket) * CHART_H, sum > 0 ? 2 : 0) : 0;
           return (
             <div key={b.bucket} className="flex-1 min-w-0 flex flex-col items-center group relative">
-              <div className="w-full flex flex-col justify-end" style={{ height: '100%' }}>
-                <div className="w-full rounded-t-sm overflow-hidden flex flex-col" style={{ height: `${Math.max(hPct, sum > 0 ? 2 : 0)}%` }}>
-                  {keys.map((k, i) => {
-                    const v = total(b.segments[k] ?? zeroCounters());
-                    const segPct = sum > 0 ? (v / sum) * 100 : 0;
-                    return segPct > 0 ? <div key={k} style={{ height: `${segPct}%`, background: colorFor(k, i, groupBy) }} /> : null;
-                  })}
-                </div>
+              <div className="w-full rounded-t-sm overflow-hidden flex flex-col" style={{ height: barPx }}>
+                {keys.map((k, i) => {
+                  const v = total(b.segments[k] ?? zeroCounters());
+                  const segPx = sum > 0 ? (v / sum) * barPx : 0;
+                  return segPx > 0 ? <div key={k} style={{ height: segPx, background: colorFor(k, i, groupBy) }} /> : null;
+                })}
               </div>
               {/* Tooltip (decorative — chart summary is exposed via aria-label) */}
               <div aria-hidden="true" className="pointer-events-none absolute bottom-full mb-1 hidden group-hover:block z-10 whitespace-nowrap bg-slate-800 text-white text-[10px] rounded px-1.5 py-1 shadow">